Fun House- There's a black square in the center of the home base podium- was that intended to be used as a game clock?
This was originally a single-character Eggcrate readout. In two pilots/test shows that made it to air (plus at least one that didn't, which played the front game for cash and had an absurd budget,) all of the prize tags had a "barcode" on the back. The tag which triggered the Power Prize was not shown to the home audience before the run; rather, at the end of it, JD would take the prize tags the team had snagged, and stick them, one by one, into a slot above the center display to "read" the barcode. On one of the test shows, the center display would beep and boop while flashing some different characters, then either the buzzer or the Power Prize siren would sound. On the other, a shot of Tiny would be superimposed over the display after the beeping and booping, and he would either say "Sorry!" or "You Win!" or things to that effect. (The unaired pilot had the Power Prize tag claiming everything in the Fun House, to the tune of $25,000. Like I said, absurd.)
The two aired pilots also had some cosmetic changes around the set, a clock that counted down in tenths of seconds, and every stunt in the front round earned the losing team runner-up points, like the "key game" in the UK version.
EDIT: Here's the unaired pilot, which, contrary to my memory, did not have the center display yet, but did use the barcode gimmick.